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Naozumi Teramoto Toyoki MotoyamaRyutoku Yosomiya Mitsuhiro Shibata 《European Polymer Journal》2002,38(7):1365-1369
Amylose was etherified with 1-bromopropane in DMSO. The degree of substitution (DS) was varied by altering the feed ratio of 1-bromopropane. The structures of the products were characterized by IR and 1H-NMR spectroscopy. When the molar feed ratio of 1-bromopropane to hydroxyl groups of amylose was beyond 7.5, the hydroxyl groups were completely substituted with propyl ether groups. The etherified amylose with DS 1.9 showed a glass transition temperature (Tg), and that with DS 2.3 or 3.0 showed both Tg and melting temperature (Tm) (DS 3.0 means complete substitution). The etherification imparted melt processability and solubility in nonpolar organic solvent to amylose. 相似文献
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Morphological studies of a hydrogen-bonded LC polymer obtained by photopolymerization in LC solvents
Hideyuki Kihara Corresponding author Toshiaki Miura Ryoichi Kishi Takashi Yoshida Mitsuhiro Shibata Ryutoku Yosomiya 《Liquid crystals》2013,40(7):799-809
Anisotropic morphologies and the phase behaviour of a hydrogen-bonded LC polymer obtained by photopolymerization in two kinds of LC solvent are discussed. The hydrogen-bonded LC monomer, 4-(6-acryloyloxyhexyloxy) benzoic acid (A6OBA), was photopolymerized in 4-cyano-4′-hexyloxybiphenyl (6OCB) and in 4-cyano-4′-undecyloxybiphenyl (11OCB), which show a nematic phase and a smectic A phase, respectively. After photo-polymerization, the LC media were removed by extraction and the pure polymer was observed by scanning electron microscopy. SEM images showed that the polymer possessed fibrous morphology with a fibre diameter of a few micrometers, based on polymerization-induced phase separation. The overall geometries reflected typical LC characteristics such as schlieren and focal-conic fan textures. It was found that the hydrogen bond between benzoic acid groups in the monomer was rigid enough to fix the anisotropic phase-separated structure forming during the early stage of phase separation; however, it could not permanently maintain the fibre structure due to dissociation at elevated temperature. X-ray measurements revealed that a well developed layer structure of the hydrogen-bonded mesogen existed in the polymer obtained from the smectic phase of 11OCB, whereas a polymer layer structure could develop only partially from the nematic phase of 6OCB. 相似文献
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Shanju Zhang Yubin Zheng Zhongwen Wu Mingwen Tian Decai Yang Ryutoku Yosomiya 《Macromolecular rapid communications》1997,18(8):729-732
The novel poly(aryl ether ketone)s were synthesized by nucleophilic substitution reactions of 4,4′-difluorobenzophenone with 4,4′-biphenyldiol and chlorohydroquinone. As expected, the copolymers have lower melting transitions than the biphenyldiol-based homopoly(aryl ether ketone) because of the copolymerization effect of the crystal-disrupting monomer chlorohydroquinone. Copolymers containing 50 and 70% biphenyldiol show two first-order transitions which are associated with the crystal-to-liquid crystal transition and the liquid crystal-to-isotropic transition. 相似文献
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Naozumi Teramoto Toyoki Motoyama Ryutoku Yosomiya Mitsuhiro Shibata 《European Polymer Journal》2003,39(2):255-261
High amylose corn starch (HACS) was etherified with 1-bromopropane in dimethyl sulfoxide. The structure of the products was characterized by infra-red and 1H-NMR spectroscopy. The degree of substitution (DS) on glucose unit calculated from 1H-NMR spectrum was varied from 0.9 to 2.7 by changing feed ratio of 1-bromopropane to HACS. Thermogravimetric analysis reveals that the etherified HACS has a higher decomposition temperature than unmodified HACS. Differential scanning calorimetry analysis reveals that the etherified starch has a clear glass transition temperature which decreased with increasing DS, and that no melting point is observed. This result demonstrates that the etherified HACS mainly consists of amorphous region. The biodegradation rate decreases with increasing degree of etherification. 相似文献
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Morphological studies of a hydrogen-bonded LC polymer obtained by photopolymerization in LC solvents 总被引:1,自引:0,他引:1
Hideyuki Kihara Toshiaki Miura Ryoichi Kishi Takashi Yoshida Mitsuhiro Shibata Ryutoku Yosomiya 《Liquid crystals》2003,30(7):799-809
Anisotropic morphologies and the phase behaviour of a hydrogen-bonded LC polymer obtained by photopolymerization in two kinds of LC solvent are discussed. The hydrogen-bonded LC monomer, 4-(6-acryloyloxyhexyloxy) benzoic acid (A6OBA), was photopolymerized in 4-cyano-4'-hexyloxybiphenyl (6OCB) and in 4-cyano-4'-undecyloxybiphenyl (11OCB), which show a nematic phase and a smectic A phase, respectively. After photo-polymerization, the LC media were removed by extraction and the pure polymer was observed by scanning electron microscopy. SEM images showed that the polymer possessed fibrous morphology with a fibre diameter of a few micrometers, based on polymerization-induced phase separation. The overall geometries reflected typical LC characteristics such as schlieren and focal-conic fan textures. It was found that the hydrogen bond between benzoic acid groups in the monomer was rigid enough to fix the anisotropic phase-separated structure forming during the early stage of phase separation; however, it could not permanently maintain the fibre structure due to dissociation at elevated temperature. X-ray measurements revealed that a well developed layer structure of the hydrogen-bonded mesogen existed in the polymer obtained from the smectic phase of 11OCB, whereas a polymer layer structure could develop only partially from the nematic phase of 6OCB. 相似文献
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Junbo Gao Ke Li Wanjin Zhang Ce Wang Zhongwen Wu Yiping Ji Yao Zhou Mitsuhiro Shibata Ryutoku Yosomiya 《Macromolecular rapid communications》1999,20(10):560-563
Monodispersed phenyl-capped trianiline and tetraaniline were successfully synthesized by the reactions of diphenylamine with acetaldehyde-based Schiff's bases of N-phenyl-1,4-phenylenediamine and 1,4-phenylenediamine, respectively, in the presence of ammonium persulfate and hydrochloric acid, subsequent deprotonation and reduction with phenylhydrazine. The reaction mechanism probably involves the slow hydrolysis of the Schiff's bases and subsequent oxidative coupling reactions of the formed ammonium salts with diphenylamine at pseudo-high dilution condition of the salts. 相似文献
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